<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<script>
			//js中所有定义变量var
			var x=10;
			var y=20;
			
			console.log(x+y);
			
			var a=10,b=20
			console.log(a*b)
			
			var x=100;//变量可以重复定义--弱语言
			console.log(x);
			console.log(typeof(x))
			
			var x="abc";
			console.log(typeof(x))
		
			
		</script>
	</head>
	<body>
	</body>
</html>
